What does INT 10H do?
Use INT 10H function calls to: – Clear the screen. – Set the cursor position. – Write characters to the screen in text mode. – Draw lines on the screen in graphics mode.
What is the function of INT 10H with AH 02h?
INT 10h, 02h (2) Set Cursor Position Sets the cursor position (row and column) for a specified display page.
What does int 21h mean in assembly language?
int 21h means, call the interrupt handler 0x21 which is the DOS Function dispatcher. the “mov ah,01h” is setting AH with 0x01, which is the Keyboard Input with Echo handler in the interrupt.
What is the function of 02H of INT 21h?
INT 21h – The general function despatcher
| Action: | Outputs a character to the standard output device. I/O can be re-directed, but prevents detection of ‘disc full’. |
|---|---|
| On entry: | AH = 02h DL = 8 bit data (usually ASCII character) |
| Returns: | Nothing |
| Notes: |
What is mov ah 02H in assembly language?
MOV AH, 02H; request display character. MOV DL, CHAR; character to display. INT 21H. – Display character in D2 at current cursor position. The tab, carriage return and line feed characters act normally and the operation automatically advances the cursor.
What is the function of 4ch of INT 21h?
INT 21h – The general function despatcher
| Action: | Writes a string to the display. |
|---|---|
| On entry: | AH = 09h DS:DX = segment:offset of string |
| Returns: | Nothing |
| Notes: | The string must be terminated by the $ character (24h), which is not transmitted. Any ASCII codes can be embedded within the string. |
What is INT 80h in assembly language?
INT is the assembly mnemonic for “interrupt”. The code after it specifies the interrupt code. (80h/0x80 or 128 in decimal is the Unix System Call interrupt) When running in Real Mode (16-bit on a 32-bit chip), interrupts are handled by the BIOS.
What is the function of 4CH of INT 21H?
What is the function of INT 21h with AH 01h?
This simply means that you are using function 01h of the Interrupt type 21… where 01h is as you said is to read character from standard input, with echo, result is stored in AL. if there is no character in the keyboard buffer, the function waits until any key is pressed.
What is the function of 4CH of INT 21h?
What is the function of 0Ah of INT 21h?
INT 21H functions
| Function number | Description |
|---|---|
| 09h e.g. mov ah,09h int 21h | String output: Send a string of characters to the standard output. DX contains the offset address of string. The string must be terminated with a ‘$’ sign. |
| 0Ah | String input |
What is int x80?
int 0x80 Definition int 0x80 is the assembly language instruction that is used to invoke system calls in Linux on x86 (i.e., Intel-compatible) processors. An assembly language is a human-readable notation for the machine language that a specific type of processor (also called a central processing unit or CPU) uses.
What is syscall int 0x80?
This answer is not useful. Show activity on this post. int 0x80 is a better terminology to indicate its a system call to the kernel to tell it to do something. The meaning and interpretation are interchangeble, ‘make a syscall’ or ‘issue int 80h’.
What is the function of 09h of INT 21h?
What does the INT 21h accomplish if ah contains 4CH?
int 21h is the second line of assembler code. The software interrupt 21h is called. This interrupt, when given the value of 4ch in AH (as is the case here), causes the program to exit immediately. END denotes the end of the program.
What is sys_exit?
The functions of the form sys_exit() are the actual entry points to the kernel routine that implements the function you think of as exit(). These symbols are not even available to user-mode programmers.
What is the use of syscall and INT 80h and where it is used?
On the Intel family of microprocessors, such as the Pentium, int 80h is the assembly language op code for interrupt 80h . This is the syscall interrupt on a typical Intel-based Unix system, such as FreeBSD. It allows application programmers to obtain system services from the Unix kernel.
What does syscall mean in assembly?
Assembly language programs request operating system services using the syscall instruction. The syscall instruction transfers control to the operating system which then performs the requested service. Then control (usually) returns to the program.